This invention relates generally to an undercarriage sound reducing idler for track-type vehicles and more particularly to such an idler that has a resiliently mounted tread surface on the idler.
Environmental regulations, both in the United States and in other countries, are increasingly being directed to the suppression of noise emitted by construction equipment such as track-type tractors. In track-type tractors, the undercarriage, i.e., the track assemblies, support rollers, track tensioning assemblies, drive sprockets and idlers, are frequently a major contributor to the overall noise signature of track type equipment.
A great amount of effort has been directed to noise abatement strategies in undercarriage assemblies. For example, U.S. Pat. No. 3,937,528 issued Feb. 10, 1976 to Donald E. Clemens et al., titled SEGMENTED AND CUSHIONED IDLER FOR TRACK-TYPE VEHICLES AND METHOD FOR CARRYING SAME, and assigned to the Assignee of the present invention, describes a support idler directed to reducing the noise level of an endless track during operation of a vehicle. More specifically, Clemens at al. describes an idler having a plurality of arcuate segments circumferentially mounted about a peripheral flange of the idler hub and an elastomeric strip disposed between each of the arcuate segments and the peripheral flange. Each of the arcuate segments is mounted to the peripheral flange by a plurality of bolts. However, during vehicle operation, the elastomeric strips interposed between the arcuate segments and the peripheral flange are compressed during each rotation of the idler. The resultant resilient cyclic compression and recovery of the elastomeric strip during operation of the vehicle eventually results in relaxation of the bolt tension, or stretch, developed when mounting the arcuate segments on the hub flange. This may cause the attachment bolts to eventually loosen. The present invention is directed to overcoming such problems.
In one aspect of the present invention, a track-type vehicle idler assembly is disposed for rotation about an axis. The idler comprises a hub with an annular flange, an endless chain with a plurality of interconnected segments is mounted on the annular flange of the hub and at least one elastomer is positioned between the endless chain and the annular flange of the hub.
In another aspect of the present invention, a track-type vehicle idler assembly is disposed for rotation about an axis. The idler comprises a hub with an annular flange, an endless chain with a plurality of interconnected segments is mounted on the annular flange of the hub and at least one assembly with an elastomeric portion is positioned between the endless chain and the annular flange of the hub.
In yet another aspect of the present invention, an endless chain assembly for use with a track-type vehicle idler is disclosed. The endless chain assembly comprises a plurality of interconnected segments. The segments are positioned relative to one another so that a substantially continuous outer bearing surface is defined.